Fish-ladder



J. A. RICHARDSON.

- FISH LADDER.

(No Model.)

N0.530,655. Patented Dec. 11,1894.

' UNITED STATES PATENT OFFICE.

JAMES A. RICHARDSON, on SAN FRANCISCO, CALIFORNIA.

FISH-LADVDFER'.

SPECIFICATION forming part Of Letters Patent No. 530,655, dated December 11, 189 4.

Application filed July 21,1894. Serial lie. 518,261. (No model.)

v To aZZ whom it may concern:

Be it known that I, JAMES A. RICHARDSON, a

citizen of the United States, residing in the city and county of San Francisco, State f of California, have invented an Improvement in Fish-Ladders; and I hereby declare the following to be a full, clear, and exact descrip tion of the same. V Y

My invention relates to improvements in those structures known as fish-ladders which are adapted to dams and other obstructions in rivers, so as to allow the fish to pass up over the dam into the water above.

It consists in certain details of construction I which willbe more fully explained by-reference to the accompanying drawings, in

' aboveeach of these transverse rifles.

which-- Figure 1 is a vertical longitudinal section taken through the ladder, showing one form of the structure. Fig. 2 is a view showing another form of the same. Fig. 3 is a modification. Fig. 4 shows the rifles in an open cut.

The object of the invention is to provide a means for enabling the fish to pass up over dams and other obstructions, to form resting places for them on the way up, and to so con-- struot the device that it is guarded from breakage by timber and. drift which may come down the stream during high water.

A is the inclined channel of the fish-way which is constructed of as great width as possible so that the fish will readily find the lower end of it as they come up, the width depending upon the volume of water and size of the stream. This incline may be similar to the apron, so-called, which is often made to extend from the edge of the dam downwardly, or it may be made in a series of approximately horizontalsteps or platforms with approximately vertical risers between each, as

gain strength to surmount the next rifle, or

to receive them in case of failure and prevent 'In streams which are notliable tobe clogged by drift-wood or badly afiected by sudden freshets,'the'se pocketsmay be made-by building up a series of low rifles D (as shown in Fig. 3) transversely extending across the incline or platorm from side to side, the heights to depend on sine of streamand volume of water, 850. Side walls F are alsobuilt'up ofti'mber or other material, and'thus inclos'e the spaces between each of the transverse rifles, and wherever the water is free from driftwood this will be suflcient to form the proper depressed spaces The water flowing over these, will first fill these wells, and then wilhflow in acomparatively smooth current over the successive obstructions or rifles D until it reaches the surface below, and fish attempting to pass up this way will, after surmounting each of the obstructions, fall'into the comparatively quiet their being carried entirelyout of the fish-way.

pool and eddy beneath the next one, where aprons are so inclined that any heavy timber or other material coming down the stream, and

passing down the fish-way, will strike these aprons and will be thus guided over the tops of the rifles an d prevented from striking them with force so as to break them down and sweep them out.

- In order to make the fish-way available to fish which always come up to the very foot of the dam or'obstruction, I remove the lower part of one of the sides, preferably toward the center of the stream, as shown in Fig. 2, so that the water flowing down the fish-way may also flow out over this side, and, if desired,=

similar rifles and wells or pools may be made upon this side discharge, although this part will be so nearly down to the level of the wa. ter below the dam that a simple incline over which the water will flow, will be sufiicient, as the current is much less swift where it is diverted from the main direction of How, and can be easily surmounted by the fish, and after reaching the first pool, they are in position to then pass up the ladder in the usual manner.

In Fig. 4, I have shown the riffies made in an open cut through the dam. In this case the rifiies increase in height from the outlet to a level with the top of the dam, and the pools are of increasing depth from the lowermost when the fish enter, to the uppermost which is nearly or quite on a level with the' top of the dam. A gate (:1. controls the flow of water through the way, and reduces the current over the uppermost riffle. The fish, after passing over the uppermost riffie', will then pass beneath the gate into the water above the dam. Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-- 1-. A fish ladder consisting of an inclined imperforate apron extending from the top of the dam to the bed of the stream beneath, and having transverse approximately vertical obstructions at intervals in its surface whereby wells or pools of quiet water will be formed in the spaces beneath the obstructions while the rapid flow of water passes above them.

2. A fish ladder consisting of an inclined imperforate apron formed with oifsets extending from the water above the dam or obstruction to that belowit, transverse obstructing riffies comprising approximately vertical risers built across the apron whereby wells or pools of comparatively quiet water are formed b'eneath each riffle, while the main body of water is allowed to flow over said pools without imparting its motion to the water therein.

3. A fish ladder consisting of an inclined im perforate apron, approximately vertical riffles extending across the same so as to provide spaces back of therifiles in which the water collects and backsup to form quiet wells or pools, while the main body of water flows over the top of the riffles, and inclined planes or aprons extending backwardly from the tops of the riffles adapted to protect the latter from driftwood and logs which may pass through the fish-way.

4. A fish ladder consisting of approximately vertical riffles placed at different levels in a channel or water-way, with their upper portions below thesurface of the water whereby the spaces between the riffies form wells or pools of quiet water while the more rapid current flows over the top of the riffles, without disturbing the quiet pools.

5. A fish ladder consisting of riffles fixed transversely in a cut or channel in the dam or obstruction with their upper portions at dilferent levels and below the surface of the water whereby wells or pools of quiet water are formed between the rifiles while the more rapid current flows over the top of the rifiles without disturbing the water of the pools, and a gate above the uppermost riffle.

In witness whereof I have hereunto set my hand.

JAMES A. RICHARDSON.

Witnesses:

S. H. NoURsE,

H. F. ASCHEOK. 

